Furnace for burning fine fuel



Nov. 9 1926. I V 1,606,719

J. POLLOCK FURNACE FOR BURNING FINE FUEL Filed April 25, 1925 amun ;tot

V /WW Fate-med Nov. 9, 1925.

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JAiJrEsPOLLOCK, or NEW YORK', Ni Y.

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Application filed Apn1"25,`19"`25. i Serial No. 25,758. 7

wherein fine fuel is blown upwardly into ai furnace chamber and burned' in suspension, air in suitable volume. to insure complete combustion being admitted at Various points in. the furnace. In such a furnace, it is portant that theupward pressure of theair ant 'gases in the furnac'e be suficient to maintain the fuel in suspension without be ing so great as to blow unconsumed mate rial out .at the top 'of the furnace. The pressure of the air enteringthe furnace can [be readily controlled by suitable* Valves, shown in the patent referred to; but it is also important to provide means for controlling the flow of gases passing from the furnace chamber to the stack, because the suction occasioned by the upwardfiow of gases in the steel: affects the pressure of the air and gases in the furnace chamber. The purpose of the 'present invention is to provide means for stabilizing the pressure in the furnace chamber, and this is 'accomplished by conducting the gases issuing from the top of the furnace chamber downwardly through a large fine to a point at orbelow the level of the burners in the furnace chamber, and by providing' atthe outlet of this fine a valve or damper by' which the draft through the furnace can be controlled. Thus, the columns of hot-gases in the fur- .nace chamber and in the downwardly extending flue'tend to rise and balance one another, and by suitably' adjusting the damper to regulate the out-flow of gases to the iii-put of air, the pressure in the furnace chambercan be maintained at the proper dygree' for holding the fuel in suspension in the chamber until it is consumed." Where the gases pass from the' furnace 'to a stack, tarougha heating device such; as a boiler, thestack will preferably be made short in order not to create a strong draft; The draft throughthe staclr maybe further 'controlled by the damper. Tl`1us,'in the normal operation of the furna ce, only a sufficient natural draft through the stack will be maintained to draw the gases through the boiler or other heatutilizing device.

In the a'ccompanying 'drawing, I .have

shown a central vertical section through a' furnace of the t e illustrated in m rior V .1 Y P patent, and also through a flue,-stack ,and boiler.

In the drawing, a indicates a. furnace chamber, Circular in 'crosssection and grad- 'ually enlarging from' the bottom toward the top, and provided withinlet openings 1 at Various points in its height 'through` which alr may be injected by means of' pipesor nozzles 2. At the bottom"of the furnace is shown a. pipe 3, having therein a worm conveyer 4& for feeding coal'dust to 'a pipe 5, havl ng :a 1 1o zzlei6, extending 'upwardly through an openmgat the bottom of the chamber. A r forced through a pipe 7 blows the coal tipwardly into the chamber, The pipe 8 connects with a-'pipe 9, surrounding the" nozzle, 'and air admitted through the pipes 8 and 9 blows the fuel upwardly and holds it 1Il suspension, all "as explained .in my. patent referred to. In the lower' part of the wall oflthe furn'ace chamber, a short distance*above the fuel nozzle, suitable burners 10 are provided for' igniting the fuel. After the fuel has become ignited' and the furnace has becomewell heated, these burners may, if desired, be shut offand the incoming fuel will then be ignited by the burning fuel and gases in the chamber; or the oil fiow to the burners maybe cutoif and the air supplv continued, to' supply additional air ,to the furnace. The gases pass from the top' of the furnace chamber into a downwardly extendingflue b, adjacent the furnace chamber. As shown, one wall. 1 1` of the'` fiue o1ns` the upper end 'of the fu'rnace chamber and extends over the; chamber and thence downwardly to ahorizontal' walllz?, and the opposing wall 13 of the fine eXtends fromthe top of the furnace chamber downwardlg to the floor 14 ofa settling chamber 15. The wall 12 is shown slightly higher than the burners '10, and a gate or valvec, slidabie in snitable`v`erti'cal guideways 16, .is adanted to serve, 'as a .damper for regulating the flow b upper portion through which gases .may flow to a heat-utilizing; device,'su ch as the tubular 'boiler 18, 'shown in the drawing, and.

'from thisdevice thega'ses 'flow to a staclr "of gases from the fine?) into' tl'ie horizontal jpassage'way or' settling ,chamber 15, The 'setthng chamber 1 5 has an opening 17 in its lili) 'and to supply the necessary Oxygen forin-y suring combustion of all of the fuel, air in to theproper point, the outward flow of gases' from the line b into [the settling chamber and thence to the staclr through the heatutilizing device, may be regulated 'so as to maintain a` practically constant pressure ,in the-,furnacechamber. The gases flow beneath the valve ordamper cinto the settling chamber 15, and any ash carried there from the furnace Will settle in this chamber and may be removed 'through 'a door 2l. The stack 19, stated, 1s pefcrably made short sothat the draftcreated 111 the stack Wlll beflslight and only sufficient to draw the gases through the heat-utilizing device 18.

, This draft.may be'regulated by the height V of the stack Well as by the damper 20.

. Thus,with thearrangement' described, the

"pressure in` the combustion chamber can be -il m .maintained constant,, whereas if the gases Were allowed to flow freely through a etaclc to the atmosphere,the paessure at the top of the combustion chamber would be lowered 'by t) e'suction and Would not be uniform, as

the gases Would take the shortezt course out 'of the chamber. By the method herein described, a certain amount of back pressure is maintained over the combustion chamber,

,and the prezsure is substantiallyequal at all points across the top of the furnace,'which is essential for maintaining the fuel in suspension until itis completely consumed.

What I claim is:

i. 'In a furnace for burning fine fuel in suspension, a `vertically arranged 'combus- -tion chamber of progressively increasing cross-sectional area from the bottom to the top, means in thelovver part of the chamber for bloiving air and'fuel upwardly therein, 'a flue, forming a continuation of said chamber. and extending from the top thereof downvvardly adjacent said chamber, ,said tlue having an outlet in'` itslower, part,`azstach connected to theflue for carrying off` the v 'gases from the furnace, and means forrestricting the flow of gases through the 'ap.-

paratus. v

2. In a furnace for burning' fine fuel in suspension, a vertically arranged combustion chamber of progressively increasing cross- 'sectional area from the bottom to the top,

means inthe lower part of the chamber for blowing air -and fuel upwardly therein, a

,,flue forming a continuation of said chamlower end of said flue.

ber and eXtending from the top thereof at the downwardly, and a gate or d p 3. In a furnace for burning fine fuel in suspensiom a vertically arranged combustion chamber of p'rogressively increasing cross. sectional area 'from the bottom to the top, means in the lower partof the chamber for? blowing air and fuel upwardly therem, a'

,burnerin .the lower .part of sa'dchamber, a line forming a continuation of said chamber andextending from the 'top thereof down Wardly to a point below the'burner, and a gate or damper controlhng the outlet of said 4. In a furnace for burning fine fuel in .suspension, a `vertically arranged combustion' chamber of progresslvely increasing cross'.

sectional area from 'the bottom to the top,

means in the lower part of the chamber for I blowing air and fuel upvvardly therein,

aburner in the lower part 'of said chamber,

a flue extending from the top of said chamber downwardly and having a lateral outlet oppositethelovver part of said 'chamber, and

a valve or gate adjacent the upper Wall of said outlet for restricting the size. of the outlet. y

5. In a ,furnace for burning line fuel in suspension, a vertically arranged combustion chamber of progressively increasing crosssectional area from the bottom to the top, means in the lower part of the chamber for blowing air and fuel upwardly therein, a burner in the lower part of said chamber,

a flue extending from the top of said chain ber dovvnwardly 'and having a lateral outlet opposite the lower part of said chamber, a

valve or gate adjacent the upper Wall of said outlet' for restricting the size of the outlet, and a settling chamber connected to thefiue through said outlet.'

6. In a furnace for *burning fine fuel in' suspension, a vertically arranged combustion chamberof progressively increasing crosssectional' area from the bottom to the top,

means in the lower part of the chamber for blowing` air" and fuel upwardly therein, a burner in the lower' part of said'chamber, a fine extending from thetop of said' cham-ber downwardly and having a lateral outlet op-` positethe lower part of said chamber, a

said outlet for restricting the size of the ontlet, a settling chamber connected to the flue through said outlet, and a relatively short stack connected to said settling chamber.

in testlmony whereof I hereunto affix my signature.

` JAMES Ponco/iz..

" ioo valve or gate adjacent 'the upper wall of I 

